1.) If this is CEO, there must be Board of Directors (In case of company), Approach them. make aware them with your situation.
2.) Talk to other staff members, Get support, if they are also facing same problem, they will definitely help you.
3.) If nothing works you have two choices:
a) Can proceed for legal actions. (Check appointment and offer letter, because most of the clauses are always in the favour of company). If you think you can spare lots of time.
b) Forget all this as a bad dream, Start looking for new position, If you possess good skills under your profile, you will get another one soon.

Regds,

Sukhvinder S. Bhatia